In December, we told you that Disneyland’s Big Thunder Mountain Railroad would be closing this month for a major renovation. Now, crews are beginning to prepare for the overhaul, which will cost an estimated $4 million. This is the first major refurbishment of the attraction in more than three decades.

On Monday, Big Thunder Mountain will close and remain closed for at least nine months. Crews will add new ride vehicles, repaint sections of the mountain and replace old track – however, the route will remain the same. Additionally, workers will make upgrades to the sound and lighting and create a larger loading and unloading dock for riders.

The Big Thunder trail that leads guests from the attraction to Fantasyland will also close on Monday, and remain closed for 11 days. Afterwards, the trail will be closed most weekdays except during the holidays but will reopen in April.

A reopening date for the attraction has not been announced, but we will let you know when the ride will reopen when the information becomes available.